Intermitant AC
I just went through this on a trip to Idaho with the outside temps in the 90 -> 100 degree range. Here's the deal, in the fuse panel next to the drivers left knee, there are a half a dozen or so large fuses. On my truck, the connector that the AC blower fuse plugs into, the leads had spread apart. I used a screw driver to close the gap between the leads, and problem solved.
I hope this helps,
Brian